Sunday, March 4, 2012

Statistical review: who were the best teams and players

Leading into the last two games this weekend, I'm taking a break from my own badly written melodrama and attempting a more dry review of the teams and the players from a statistical perspective.

Most of you who go to FIFA.com are probably aware of the Castrol index, which ranks the players with its own scheme designed for rewarding players based on their individual performances on certain positions of the field in a game. I'm not here to talk about the Castrol index, especially as I don't know its formula (trade secrets).

However, the main issue with the Castrol index is how the scores are in no way based on how individuals play together as a team with a collective goal in mind. Dr. Jordi Duch devised his own ranking scheme to counter this, and this is what I'll discuss, since I know how it works.

The premise is brilliant, he tracks every passing movement that a team performs, from the moment someone gets the ball, to the moment a ball is lost, or a shot is taken. In this way, Jordi is able to build a passing network of how the players interact in a game. He also 'weighs' the interactions between the players based on the number of passes they had between them, and based on how many of the collective passing movements ended in a shot (resulting in either a goal or not).

The result is that he can score individual players based on how 'central' they were (he calls it 'flow centrality') to the entire team's ability to score goals, and he can also give the team a rating of its own, based on its best players. Jordi tested his rating on Euro 2008, with a lot of success, he matched player and team performances to media expectations.

Worst and Best of the last 16
I'm going to start with some of the teams that never made it out of the group stage.
I show here the top four teams, and the worst three teams in terms of team rating. The ratings themselves range from 3 to -3, but a value of 0 means plain average, values of 1/-1 means good/bad, whilst values of 2/-2 means bunch of geniuses/idiots. Not only do I show the teams average rating over three games, I show their opponents average rating, which indicates (indirectly) how well the teams did defensively.

TeamAverage RatingAverage Opponent Rating
Ivory Coast
1.1
0.5
South Africa
1.1
1.1
Italy
0.9
-1.2
Denmark
0.9
1.6
Switzerland
-0.1
0.9
Honduras
-0.8
1.3
New Zealand
-1.5
0.9

Of the top four teams that made it out, Italy has got to feel the most done-over. Not only did they do well (many teams that 'graduated' didn't get a rating of 1), their opponents sucked, even Slovakia with its three goals on three good chances allowed Italy to play way better than them.


TeamAverage RatingAverage Opponent Rating